1. Field of the Invention
This invention generally relates to a check valve module in a shock absorber with adjustable damping force, the shock absorber comprising a cylinder, an axially movable piston rod with a piston connected thereto, a number of fluid chambers with capacities which can be changed relative to one another as a function of the movement of the piston rod relative to the cylinder, and fluid connections between at least two of the fluid chambers, wherein at least one valve has a check valve module. The check valve module is designed with at least one valve seat, whereby a valve check element can be elastically applied against the valve seat in a check position, whereby this valve check element can also be adjusted by means of a field coil in opposition to the closing force of at least one spring in a number of positions, whereby the spring(s) is/are a unit of a row inside the check valve module, and possibly an intermediate module which includes a control chamber discharge valve body and a supplemental discharge valve body.
2. Background Information
German Laid-Open Patent Application No. 41 14 305 discloses a check valve module which has a number of springs which apply a prestress to the individual parts of the check valve module. In mass production, the installation of the individual parts usually entails some positioning problems, since the individual parts must usually be introduced by opening the housing of the check valve module. The parts are small and are correspondingly difficult to handle. All the individual parts between the check valve plate and the magnet armature must be inserted into one another. During assembly, the individual parts, in particular those which are inserted in the armature, can often slip out of the armature and assume an uncontrolled position inside the check valve module. Under some circumstances, it then becomes impossible to correctly install the armature. All the parts must thence be carefully removed from the housing and the assembly process must be repeated.
The type of assembly described immediately above may be acceptable for the manufacture of a prototype, but it appears to be out of the question for efficient mass production operations in which, nowadays, the allowable number of defects tends to be measured in terms of defects per million finished products.